Study On Factors Affecting Electricity Production And Sewage Purification Of Bio - Cathode Microbial Fuel Cell

Biocathodes, which use microorganisms to assist cathodic reactions in microbial fuel cells （MFCs）, could decrease the cost and increase the operational sustainability. However, the limitation of lower performance on power generation calls for more work before the wide use of the biocathode. Therefore, the objective of this present study is to enhance the performance of the biocathode, the MFC with biocathode were constructed using NO₃^- and O₂ as the electron acceptor, and the effect factors of power production were studied,at the same time, we simultaneously realize effective electricity generation and nitrification in the cathode of two-chamber microbial fuel cell,discuss the nitrifier competed with electrochemically-active bacteria for oxygen.Following results were obtained: （a） When a NO₃^- inner biocathode was used, the NO₃^--N removal rate was 8¹0 mg/d and the maximum power density was 0.095 W/m³. When a NO₃^- outer biocathode was used, the maximum power density further increased to 0.54 W/m³ resulting from a decrease in cathode resistance;When the external resistor （10Ω） close to the total resistance （6 8Ω）, denitrification rate is faster and accumulation of nitrite nitrogen is less; the change of external resistance didn`t impact the power generation of MFC （b） For the O₂- MFC,the COD removal rate of outer biocathode is increased from 80%（inner biocathode）to 84.6%, the maximum power density increased from 3.32 to 4.48 W/m³;The O₂-MFC’s optimal operating conditions: the external resistance is 10Ω, the enter flux is 120 mL/h, the circular flux is 16L/h,and DO is 5mg/L.（c） After inoculated nitrifying bacteria, the maximum power density decreased to 1.9W/m³, the maximum current decreased to 71mA, which illustrates that the ability of nitrifying bacteria to compete for the oxygen is better than industrial systems bacteria; After inoculated nitrifying bacteria, produce electricity and nitrification can be achieved in MFC synchronously, not only improve the aeration efficiency, but also to device integration and saving area.